History of mathematics · Maths EE idea · Accessible

Archimedes' bounds for π

A research question to start from

How did Archimedes use inscribed and circumscribed polygons to bound π, and how quickly does his method converge compared with modern series?

A starting point, not your question: change the case, the comparison or the limit until it is yours. The research-question builder helps you check it.

Why it works as a maths EE

Working through a historical method in modern notation, then measuring it.

Mathematics you would need

  • Perimeters of regular polygons
  • Recurrences for doubling sides
  • Trigonometry
  • Rates of convergence

Much of this goes beyond the DP course. That is expected in a maths EE, but you must understand and explain everything you use.

One possible line of attack

  1. Derive the doubling recurrences.
  2. Reproduce the bounds for 96 sides.
  3. Compare convergence with a modern series.

Scope and difficulty

Accessible. Accessible.

Pitfalls

  • Biography.
  • Copying historical tables without working.

Where to start reading

Search a library catalogue or a university's open lecture notes for: Archimedes method polygons pi recurrence; harmonic geometric mean. Prefer textbooks, lecture notes and journal articles to a single website, and cite everything you use (how to reference a maths EE).

Make it your EE

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